The invention provides a sgRNA combination of a targeted AHRR gene and application of the sgRNA combination, the sgRNA combination of the targeted AHRR gene comprises sgRNA1 and / or sgRNA2, the sgRNA1 comprises a nucleic acid sequence as shown in SEQ ID No.1, and the sgRNA2 comprises a nucleic acid sequence as shown in SEQ ID No.2. The invention also provides an AHRR gene editing system, a recombinant cell and a construction method thereof, and a construction method of an obese animal model, through gene editing and screening, the obtained homozygous mouse without the AHRR gene has typical obesity signs, larger body type, heavier body weight, higher fat content in vivo, and can be used for screening blood sugar and lipid reducing related drugs, and has extremely wide application value.